Technical Field
The present invention relates generally to methods and apparatuses for processing slides carrying specimens. More specifically, the invention is related to adhering specimens onto microscope slides.
Description of the Related Art
Tissue analysis is a diagnostic tool used by physicians, such as pathologists, to diagnose different types of illnesses and by medical researchers to obtain information about pathology, tissue composition, and tissue architecture. A wide range of different procedures are commonly used to prepare a tissue sample for tissue analysis. Many types of tissue are relatively soft and pliable and, thus, not suitable for sectioning. Techniques for preparing tissue samples include fixing the tissue, embedding the tissue in a material, sectioning the embedded tissue, and transferring the tissue sections onto microscope slides for subsequent processing and analyses, such as staining, immunohistochemistry, or in-situ hybridization. To section a tissue sample for optical microscope examination, a relatively thin strip of tissue can be cut from a large tissue sample so that light may be transmitted through the thin strip of tissue. An average thickness of the strip of tissue is often on the order of about 2 microns to about 8 microns.
Water is often used to facilitate transfer of the thin strips of tissue onto microscope slides. A residual droplet of water trapped between the microscope slide and the thin strips of tissue will cause the thin strips of tissue to float on the slide. The floating tissue sections of these wet slides are susceptible to movement along the front surface of the microscope slides. If the tissue samples move too far, the samples may fall off of the microscope slide. If the physician is unaware of the sample falling off of the microscope slide, a diagnosis may be made based on an incomplete test result, which may ultimately contribute to a misdiagnosis. For example, if a set of tissue samples are floating on residual water on a slide, one of the tissue samples may fall off the slide during a drying process. The tissue sample that fell off may be a tissue sample needed for a proper diagnosis.
Horizontal hotplates and convection ovens are often used to heat and dry wet microscope slides. If a horizontal hotplate is used, it may take a relatively long period of time to evaporate the water beneath the tissue sample on a horizontally oriented slide. Additionally, the contact angle between the water and the slide often increases when embedding material of the sample melts and reaches the front surface of the slide. If the microscope slide moves or is not level during this drying process, the tissue sample may move a significant distance relative to the slide and, in some circumstances, may fall off of the microscope slide. If spaced apart tissue samples (e.g., a row of evenly spaced tissue samples) move significant distances relative to one another during the drying process, a physician may become concerned that one or more of the tissue samples fell off of the microscope slide. The physician may discard that sample-bearing slide and prepare a completely new sample-bearing slide to ensure that a complete set of tissue samples is analyzed. It may be necessary to obtain additional tissue samples from the subject. Convection ovens take a relatively long time to dry slides. Conventional convection ovens can dry vertically oriented slides in about 30 minutes to about 2 hours.